val response = chain.proceed(request)

      decompress(response)
    } else {
      chain.proceed(chain.request())
    }

  /**
   * Returns a decompressed copy of the Response, typically via a streaming Source.
   * If no known decompression or the response is not compressed, returns the response unmodified.
   */
  internal fun decompress(response: Response): Response {
    if (!response.promisesBody()) {

        header("Content-Encoding", "zstd")
      }

    val decompressed = zstdInterceptor.decompress(response)
    assertThat(decompressed.header("Content-Encoding")).isNull()

    assertFailsWith<IOException> {
      decompressed.body.string()
    }.also { ioe ->
      assertThat(ioe).hasMessage("zstd decompress failed: Unknown frame descriptor")
    }
  }

  @Test

    val response =
      response("https://httpbin.org/brotli", s.decodeHex()) {
        header("Content-Encoding", "br")
      }

    val uncompressed = brotliInterceptor.decompress(response)

    val responseString = uncompressed.body.string()
    assertThat(responseString).contains("\"brotli\": true,")
    assertThat(responseString).contains("\"Accept-Encoding\": \"br\"")
  }

  @Test

public final class okhttp3/zstd/Zstd : okhttp3/CompressionInterceptor$DecompressionAlgorithm {
	public static final field INSTANCE Lokhttp3/zstd/Zstd;
	public fun decompress (Lokio/BufferedSource;)Lokio/Source;
	public fun getEncoding ()Ljava/lang/String;

///

First, we create a `GzipRequest` class, which will overwrite the `Request.body()` method to decompress the body in the presence of an appropriate header.

If there's no `gzip` in the header, it will not try to decompress the body.

That way, the same route class can handle gzip compressed or uncompressed requests.

import okio.BufferedSource
import okio.GzipSource
import okio.Source

object Gzip : DecompressionAlgorithm {
  override val encoding: String get() = "gzip"

  override fun decompress(compressedSource: BufferedSource): Source = GzipSource(compressedSource)

/**
 * Support for Zstandard encoding. Use via the [CompressionInterceptor].
 */
object Zstd : CompressionInterceptor.DecompressionAlgorithm {
  override val encoding: String get() = "zstd"

  override fun decompress(compressedSource: BufferedSource): Source = compressedSource.zstdDecompress()

    async def body(self) -> bytes:
        if not hasattr(self, "_body"):
            body = await super().body()
            if "gzip" in self.headers.getlist("Content-Encoding"):
                body = gzip.decompress(body)
            self._body = body
        return self._body


class GzipRoute(APIRoute):
    def get_route_handler(self) -> Callable:
        original_route_handler = super().get_route_handler()

    async def body(self) -> bytes:
        if not hasattr(self, "_body"):
            body = await super().body()
            if "gzip" in self.headers.getlist("Content-Encoding"):
                body = gzip.decompress(body)
            self._body = body
        return self._body


class GzipRoute(APIRoute):
    def get_route_handler(self) -> Callable:
        original_route_handler = super().get_route_handler()

    async def body(self) -> bytes:
        if not hasattr(self, "_body"):
            body = await super().body()
            if "gzip" in self.headers.getlist("Content-Encoding"):
                body = gzip.decompress(body)
            self._body = body
        return self._body


class GzipRoute(APIRoute):
    def get_route_handler(self) -> Callable:
        original_route_handler = super().get_route_handler()